title: Association genetics of wood physical traits in the conifer white spruce and relationships with gene expression.
abstract: Marker-assisted selection holds promise for highly influencing tree breeding, especially for wood traits, by considerably reducing breeding cycles and increasing selection accuracy. In this study, we used a candidate gene approach to test for associations between 944 single-nucleotide polymorphism markers from 549 candidate genes and 25 wood quality traits in white spruce. A mixed-linear model approach, including a weak but nonsignificant population structure, was implemented for each marker-trait combination. Relatedness among individuals was controlled using a kinship matrix estimated either from the known half-sib structure or from the markers. Both additive and dominance effect models were tested. Between 8 and 21 single-nucleotide polymorphisms (SNPs) were found to be significantly associated (P ≤ 0.01) with each of earlywood, latewood, or total wood traits. After controlling for multiple testing (Q ≤ 0.10), 13 SNPs were still significant across as many genes belonging to different families, each accounting for between 3 and 5% of the phenotypic variance in 10 wood characters. Transcript accumulation was determined for genes containing SNPs associated with these traits. Significantly different transcript levels (P ≤ 0.05) were found among the SNP genotypes of a 1-aminocyclopropane-1-carboxylate oxidase, a β-tonoplast intrinsic protein, and a long-chain acyl-CoA synthetase 9. These results should contribute toward the development of efficient marker-assisted selection in an economically important tree species.
authors.affiliation: Natural Resources Canada, Canadian Wood Fibre Centre, Québec City, Québec, Canada. jean.beaulieu@NRCan.gc.ca
authors.forename: Jean
authors.initials: J
authors.lastname: Beaulieu
authors.forename: Trevor
authors.initials: T
authors.lastname: Doerksen
authors.forename: Brian
authors.initials: B
authors.lastname: Boyle
authors.forename: Sébastien
authors.initials: S
authors.lastname: Clément
authors.forename: Marie
authors.initials: M
authors.lastname: Deslauriers
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Beauseigle
authors.forename: Sylvie
authors.initials: S
authors.lastname: Blais
authors.forename: Pier-Luc
authors.initials: PL
authors.lastname: Poulin
authors.forename: Patrick
authors.initials: P
authors.lastname: Lenz
authors.forename: Sébastien
authors.initials: S
authors.lastname: Caron
authors.forename: Philippe
authors.initials: P
authors.lastname: Rigault
authors.forename: Paul
authors.initials: P
authors.lastname: Bicho
authors.forename: Jean
authors.initials: J
authors.lastname: Bousquet
authors.forename: John
authors.initials: J
authors.lastname: Mackay
mesh_terms: D016000:Cluster Analysis; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D056726:Genetic Association Studies; D005838:Genotype; D015810:Linkage Disequilibrium / Q000235:genetics; D028222:Picea / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011157:Population Dynamics; D019655:Quantitative Trait, Heritable; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014934:Wood / Q000235:genetics*
chemical_list: D012333:RNA, Messenger